4. Subject has senile degenerative aortic stenosis with echocardiography derived mean gradient greater than (>) 40mmHg or jet velocity greater than 4.0 m/s or an initial valve area of less than (<) 0.8 cm2 (or aortic valve area index less than or equal to (≤) 0.6 cm2/m2). (Baseline measurement taken by echo within 90 days of index procedure).